Did Robert Jordan acknowledge or otherwise address this connection?
TL;DR: No, they are not. The source material for the Wheel of Time is extensive, and you can see a whole list of it in the Sources section of the FAQ. However, this is all historical or mythological source material, and not material from other sci-fi authors. The similarities between the Wheel of Time and other sci-fi works is because the authors of the other works drew from the same real-world source material as Jordan.
As far as the specific connection between the Aiel and Fremen, as far as anyone has ever admitted, the former are not directly based on the latter; in fact, Jordan has explicitly denied borrowing ideas directly from anyone except for Tolkien:
The reason that the Aiel and Fremen appear so similar is because Jordan and Herbert based them on the same source material. There are a lot of other similarities with Dune, as described in this FAQ section. In the case of the Aiel/Fremen, both were based very heavily on the Zulu nation, and both Herbert and Jordan borrow heavily from real Arabic language.